The present invention relates to an apparatus and to a process for gauging and controlling extruded profiled elements, particularly for extruded profiled elements made of synthetic material, such as for example extruded profiled elements based on polyvinyl chloride, both of the "rigid" and "foamed" type.
In conventional production lines for extruded profiled elements, particularly in the case of extruded items made of synthetic material, the profiled element that leaves the extrusion die is cooled so as to stabilize its shape and allow its support and movement. The profiled element is generally cooled inside appropriate structures, termed "gauges", which have a through passage shaped like the profile of the profiled element which is conveyed along said passage so as to avoid as much as possible deformations of the profile during this cooling step. Cooling is performed by circulating coolant inside channels that run in the gauges proximate to the passage along which the profiled element advances.
In order to avoid variations in the profile of the profiled element with respect to the profile defined during design, the cooling action is sometimes combined with suction at preset regions of the profile.
However, in the execution of particularly complicated profiles these solutions do not meet the most demanding application requirements of the extruded item, particularly as regards precision at sharp corners, ridges and angles of more or less than 90.degree., and surface flatness. At these regions, the techniques currently in use are not always able to compensate for the internal tensions of the profile which are the main cause of permanent deformations.
Due to this reason, the finished product may have anomalies that are no longer recoverable.
In view of this fact, in order to achieve acceptable results, setup operations, corrections, and adjustments are performed during the production of profiled elements or during forced interruptions, with a considerable waste of time and material that significantly affects overall production costs.